sort/example/parallelint.cpp
2017-11-21 18:37:15 +01:00

116 lines
3.1 KiB
C++

// Benchmark for integer sorting speed across parallel threads.
//
// Copyright Steven Ross 2014
//
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
// See http://www.boost.org/libs/sort for library home page.
#include <boost/sort/spreadsort/spreadsort.hpp>
#include <boost/thread.hpp>
#include <time.h>
#include <stdio.h>
#include <stdlib.h>
#include <algorithm>
#include <vector>
#include <string>
#include <fstream>
#include <sstream>
#include <iostream>
using namespace boost::sort::spreadsort;
#define DATA_TYPE int
bool is_sorted(const std::vector<DATA_TYPE> &array) {
for (unsigned u = 0; u + 1 < array.size(); ++u) {
if (array[u] > array[u + 1]) {
return false;
}
}
return true;
}
void sort_loop(const std::vector<DATA_TYPE> &base_array, bool stdSort,
unsigned loopCount) {
std::vector<DATA_TYPE> array(base_array);
for (unsigned u = 0; u < loopCount; ++u) {
for (unsigned v = 0; v < base_array.size(); ++v) {
array[v] = base_array[v];
}
if (stdSort)
std::sort(array.begin(), array.end());
else
boost::sort::spreadsort::spreadsort(array.begin(), array.end());
if (!is_sorted(array)) {
fprintf(stderr, "sort failed!\n");
exit(1);
}
}
}
//Pass in an argument to test std::sort
int main(int argc, const char ** argv) {
size_t uCount,uSize=sizeof(DATA_TYPE);
bool stdSort = false;
int threadCount = -1;
unsigned loopCount = 0;
for (int u = 1; u < argc; ++u) {
if (std::string(argv[u]) == "-std")
stdSort = true;
else if(threadCount < 0)
threadCount = atoi(argv[u]);
else
loopCount = atoi(argv[u]);
}
if (!loopCount) {
loopCount = 1;
}
printf("threads: %d loops: %d\n", threadCount, loopCount);
std::ifstream input("input.txt", std::ios_base::in | std::ios_base::binary);
if (input.fail()) {
printf("input.txt could not be opened\n");
return 1;
}
std::vector<DATA_TYPE> base_array;
input.seekg (0, std::ios_base::end);
size_t length = input.tellg();
uCount = length/uSize;
input.seekg (0, std::ios_base::beg);
//Conversion to a vector
base_array.resize(uCount);
unsigned v = 0;
while (input.good() && v < uCount)
input.read(reinterpret_cast<char *>(&(base_array[v++])), uSize );
input.close();
if (v < uCount)
base_array.resize(v);
//Run multiple loops, if requested
clock_t start, end;
double elapsed;
std::vector<boost::thread *> workers;
start = clock();
if (threadCount == 0) {
sort_loop(base_array, stdSort, loopCount);
} else {
for (int i = 0; i < threadCount; ++i) {
workers.push_back(new boost::thread(sort_loop, base_array, stdSort,
loopCount));
}
for (int i = 0; i < threadCount; ++i) {
workers[i]->join();
delete workers[i];
}
}
end = clock();
elapsed = static_cast<double>(end - start) ;
if (stdSort)
printf("std::sort clock time %lf\n", elapsed/CLOCKS_PER_SEC/threadCount);
else
printf("spreadsort clock time %lf\n", elapsed/CLOCKS_PER_SEC/threadCount);
return 0;
}